Peptide Reconstitution Calculator

A peptide reconstitution calculator turns three numbers into a syringe reading. You tell it the amount in the vial (in mg), how much bacteriostatic water you added (in mL), and the dose you want to measure. From those it computes the concentration, the volume to draw, and — for an insulin syringe — the number of units that volume lands on.

Everything recalculates on every keystroke, so you can try different water volumes and watch the draw change. The labeled syringe diagram marks where your draw falls, and the result is copyable so you can save it. The tool does the arithmetic only; it never suggests what dose to use.

The math behind the tool is short. Concentration is the vial amount divided by the water you added: mg ÷ mL = mg/mL. To find how much to draw, divide your dose by that concentration. To convert that draw into units on a U-100 insulin syringe, multiply by 100, because 100 units equals 1 mL.

A worked example: a 5 mg vial reconstituted with 2 mL of bacteriostatic water is 2.5 mg/mL, or 2500 mcg/mL. For a 250 mcg measurement, the draw is 250 ÷ 2500 = 0.1 mL, which on a U-100 syringe is 10 units. That is arithmetic, not a recommendation — the number that is right for you is a question for your own records and a qualified professional, not this page.

On a U-100 insulin syringe the whole barrel is 1 mL and is marked in 100 units, so each unit is one-hundredth of a millilitre. Ten units is 0.1 mL, fifty units is 0.5 mL. A U-40 syringe uses a different scale — 40 units to the millilitre — which is exactly the kind of mismatch the unit-guard is built to catch.

The calculator draws a labeled syringe and places a marker at the computed unit line, so you can hold your syringe against the picture and confirm the two agree before you trust the number.

The unit-guard is the part other calculators skip. Instead of silently returning a wrong answer when the inputs do not make sense, it stops and tells you what looks off:

• The classic 1000× error — entering a dose in mcg when the vial is in mg, or the reverse. A dose larger than the entire vial is the tell, and the guard flags it.
• A draw volume larger than the syringe can hold, so you know to use a larger syringe or split the draw.
• Zero or negative values that would produce a meaningless result.

It is an error-catching guard on the arithmetic, not a safety approval. It never says a dose is safe for you — only whether the numbers you typed are internally consistent.

The calculator gives you one number for one draw. BioTrackr keeps the whole picture: a running vial inventory stores each vial with its concentration and remaining doses, warns you before one expires, and — because it also reads your wearable data — shows whether the protocol you are running actually moved your metrics against your baseline.

If you track more than the occasional draw, that is the difference between a one-off calculation and a record you can act on. See the peptide tracker app, or pricing and the free trial.